5923570 Soldiers relaxing inside a frontier sangar, 1939 circa (b/w photo) by Unknown photographer, (20th century); National Army Museum, London; (add.info.: Soldiers relaxing inside a frontier sangar, 1939 circa. Photograph, India, North West Frontier, 1939 circa. Men from 1st Battalion, 13th Frontier Force Rifles, sit in a sangar, a temporary fortified position with a breastwork made of stone. Such positions were used to guard the heights along strategically vital roads and passes on the frontier. From an album of 168 photographs compiled by Major Wynne Howes-Roberts, 1st Battalion 13th Frontier Force Rifles, 1939-1940.); by National Army Museum ; out of copyright.